1. Field of the Invention
The present invention relates to a process and device or assembly for use in tissue repair. More particularly, there is provided an enhanced assembly that enables the attachment together or repair of portions of biological tissue, such as tendons or ligaments, on a bone surface. Such device or assembly is used in an unique way with novel components to reattach or attach tissue to bone.
2. Description of the Background Art
Soft tissues, such as tendons and ligaments, generally are attached to bone by small collagenous fibers. These connections are strong but permit the tendons and ligaments to be flexible. When a tissue, or a portion of a tissue, is torn away from the bone and requires repair, a surgeon is often required to repair the detached soft tissue with sutures which are passed through bone tunnels and tied. A number of devices have been developed for securing a ligament or tendon to a bone mass. These devices can be used in place of bone tunneling techniques. These attachment devices are usually inserted through extensive surgical incisions and, in some circumstances, by arthroscopic surgical techniques. The use of bone tunnels for repair can be difficult and generally require large open incisions. Recently, through the advent of endoscopic surgery, where the surgeon looks into a joint cavity with a telescope, there has been a trend to repair soft tissues back to bone through small incisions called portals. The unique free loop knotless suture anchor assemblies described herein facilitate this difficult and precise procedure.
A variety of devices are available for attaching objects to bone, such as screws, staples, cement, suture anchors, and sutures alone. These devices have been used to attach soft tissue, such as ligaments, tendons, muscles, as well as objects such as prostheses, to bone. A suture anchor assembly is a device which utilizes small anchors with suture materials attached thereto. A device, such as a screw, is inserted into the bone mass and anchored in place. After insertion of the anchor, the attached suture is passed through the tissue to be repaired. The tying of a knot in the suture is then required to secure the tissue to the bone. The process of passing the anchored suture through the soft tissue and tying a knot is time consuming and difficult to undertake in the tight space encountered during endoscopic surgery and sometimes even in conventional open surgery.
One example of a suture anchor assembly is disclosed in U.S. Pat. No. 5,370,662, wherein an anchor assembly includes a pre-threaded suture positioned at its posterior. First the anchor is inserted into the bone mass. The attached suture is then passed through the tissue for reattachment. The surgeon is required to tie a knot with the suture to complete the surgical process. Some suture anchors can be passed through the soft tissue first and then into the bone. Most suture anchors need to be inserted into the bone first. Only after this has been accomplished can the sutures be passed through the soft tissue. Alternatives to this procedure include non-suture soft tissue anchor systems. A few of these systems, such as those disclosed in U.S. Pat. Nos. 5,013,316 and 4,532,926, can be used arthroscopically but fixation with these devices may not be as secure as that achieved with sutures. Only a few points of fixation are possible with the non-suture type anchor since the device is relatively large. Therefore suture devices are more favorable. This type of non-suture staple device is disadvantageous in that it has been known to crack the bone during deployment, or accidentally transect the object being attached to the bone. In addition, the device itself has been known to crack or break during or after deployment.
U.S. Pat. Nos. 5,037,422; 5,224,946; and 5,236,445 all disclose bone anchor configurations for attaching sutures within openings formed in bones during joint reconstructive surgery and endoscopic surgical procedures. With all these intricate procedures, the suture itself must be inserted through a tissue mass and tied with a surgical knot to repair the soft tissue to bone.
The applicant has developed a number of mechanisms for a tissue to bone repair which are disclosed in U.S. Pat. Nos. 5,569,306; 5,683,419; 5,728,136; 5,665,112; 5,658,313; 5,720,765; and 5,709,708.
It is an object of the present invention to provide a knotless suture anchor assembly which is easy to use and install.
Another object of the present invention is to provide a free loop suture anchor assembly which allows for secure attachment of soft tissue to a bone mass without the use or requirement of tying a knot during the surgical procedure.
Still another object of the present invention is to provide a suture anchor assembly which is compact and allows a surgeon to easily guide the anchor means into the bone mass, or an anchoring sleeve if desired, to enhance the security of the repair.
Yet another object of the present invention is to provide a process whereby a plurality of free loop knotless suture anchor assemblies can be used to effectively attach or reattach tissue to bone.
Further, another object of the present invention is a mechanism for producing incisions or cuts in tissue for performing reattachment or attachment of tissue to bone using the novel anchor assemblies.
A primary feature of the present invention is to provide free loop knotless anchor assembly that includes an unique snag-type or capture means on an anchoring means which facilitates engagement of the anchor means with the free continuous suture loop, for drawing soft tissue to the bone mass.